1. Field of the Invention
The invention relates to a device for changing the stress-induced birefringence or the thickness or the stress-induced birefringence and the thickness of an optical component by elastic deformation caused by means of stress.
The invention relates also to a method for changing the stress-induced birefringence or the thickness or the stress-induced birefringence and the thickness of an optical component by elastic deformation caused by means of stress.
2. Description of the Related Art
It is known from the general specialist literature (for example Bergmann Schäfer; Volume 3—Optik; 9th edition 1993; deGryther; Chapter 4, Point 13 “Induzierte Doppelbrechung in isotropen Stoffen” [“Induced birefringence in isotropic materials”]) that it is possible by injecting pressure or tensile stresses which respectively effect at least small plastic deformations in the material to vary correspondingly the stress-induced birefringence of electromagnetic waves, for example light, in the material.
This basic technique finds a technical application in the field of high-performance optics, for example in the production of optical elements for exposure lenses in semiconductor lithography, in DE 196 37 563 A1, which describes a DUV-capable quarter-wave plate or similar. This is designed as a plane plate under stress-induced birefringence. The plane plate consists in this case of high-quality quartz glass and is loaded under tension, free from torsion and uniformly, by suitable structures, for example lever arrangements, with a plurality of parallel tensioning devices.
In this case, however, the arrangement is comparatively complicated, since it is necessary via appropriately complex structures to ensure uniform injection of the tensile stresses into the optical element, here the plane plate.
Reference may be made to U.S. Pat. No. 6,141,148, U.S. Pat. No. 3,600,611 and U.S. Pat. No. 3,867,014 for the general prior art.